Appraisal on inversion algorithm techniques in 2D electrical resistivity tomography survey data for poised mapping of subsurface features

Abstract. Analysis of non-uniqueness model in resistivity imaging data is vital in inaugurating the consistency of models. Nevertheless, such analysis is moderately unusual in resistivity imaging data set. Electrical resistivity tomography (ERT) technique is being constantly used in many scientific areas including engineering, environmental and archaeological survey. Primarily, the inversion algorithm techniques are employed on synthetic model data set with and without some random Gaussian noise, and its validity is tested by filed data set. The study was conducted in the premises of Central Institute of Mining and Fuel Research (CIMFR), Dhanbad by laying an ERT profile of 480 m length with 5 m electrode spacing using Syscal Pro (Iris instrument) resistivity meter. Two standard arrays were used in this study namely Wenner-Schlumberger and dipole-dipole array. The data set was mixed to a single array to achieve better resolution and enhanced clarification. On processing data by Prosys-II software, it was exported in Res2Dinv software for inversion. In this context, data was inverted by different algorithm techniques i.e. least square (L₂-norm) and robust inversion (L₁-norm). Exemplary results related to the heterogeneity of the resistivity structure within the high and low resistivity anomaly were obtained by robust inversion method. The obtained results are in broad agreement with the simulation model.